Thursday, July 01, 2010

NZ Influenza Surveillance: Week 25

 

 

# 4689

 

Since influenza activity usually dwindles during the summer months in the northern hemisphere (excluding the tropics), we look to countries south of the equator for influenza in June, July and August.

 


New Zealand, Australia, and South Africa are three southern hemisphere population centers with good surveillance and reporting, and from them we can sometimes can get a hint of what may lay ahead for our flu season in the fall.

 

The level of influenza in 2010 has, thus far, been low in these countries, but there are indications that it may be picking up.

 

First, a link to this week’s surveillance from New Zealand, and a couple of graphics from that report, then a link to this week’s press release from the Ministry of Health.

 

 

INFLUENZA WEEKLY UPDATE
2010/25:  21-27 June 2010

 

SUMMARY OF THIS REPORT:

•  Influenza-like  illness (ILI)  through sentinel surveillance was reported from 19 out of
20  District  Health  Boards  (DHB)  with  a  national  consultation  rate  of  29.0  per 100 000 (106 ILI consultations). 


•  One hundred and forty-two swabs were received from sentinel (26) and non-sentinel surveillance  (116).  Eight  viruses  were  identified,  three  from  sentinel:  pandemic (H1N1) 09 (2) and A (H3N2) (1), and five from non-sentinel surveillance: pandemic (H1N1) 09 (3) and A (not sub-typed) (2).  


•  Since  January  2010,  322  cases  of  pandemic  (H1N1)  09  have  been  recorded  in EpiSurv3
, six of which were reported in week 25.
  

 

 

Once again, we are seeing faint traces of seasonal H3N2 showing up in surveillance reports. 

 

Whether that represents a `last gasp’ of this strain, or is an indication of its resilience in the face of a pandemic strain, is difficult to gauge at this point.  

 

 

image

 

While still below the baseline, influenza-like activity in New Zealand has shown an increase two weeks in a row.  

 

The map below shows that the health districts of Waikato and Capital and Coast are reporting levels above the baseline, while most of the rest of the country is seeing lesser activity.

 

 

image

 

1 July 2010

Pandemic Influenza H1N1 2009 (swine flu) – Update 192

Overall influenza activity is gradually increasing and is at the level usually seen at this time of year. The pandemic influenza virus is circulating in our communities, though the rate of consultation for influenza-like illness identified through sentinel general practices remains below the baseline level.

(Continue . . .)